1. Field of the Invention
The present invention relates to a substrate having a light emitter which emits light by electron beam irradiation for an image display device, such as a field emission display, which utilizes an electron beam. The present invention also relates to an image display device using the substrate and an information display reproducing apparatus using the image display device.
2. Related Background Art
Research and development of the image display device for which a field emission type electron-emitting device, a surface conduction electron-emitting device, and the like are used is in progress for a flat panel display of application.
FIG. 13 shows an example of a display panel of the conventional image display device formed by using the surface conduction electron-emitting device. FIG. 13 is a perspective view schematically showing a structure while the display panel is partially cut off. In FIG. 13, the numeral 31 represents a rear plate, the numeral 32 represents a row-direction wiring, the numeral 33 represents a electron-emitting device, the numeral 34 represents a column-direction wiring, the numeral 40 represents a faceplate, the numeral 41 represents a glass substrate, the numeral 45 represents a metal back, the numeral 46 represents a high-voltage power supply, the numeral 47 represents a fluorescent material layer, and the numeral 48 represents a sidewall.
In the display panel of FIG. 13, a display panel is formed by the rear plate 31, the sidewall 48, and the faceplate 40. In the display panel, the row-direction wirings 32 and the column-direction wirings 34 are formed on the rear plate 31, and a multi-electron beam source is formed by arranging the electron-emitting devices 33 at nodal points where the row-direction wiring 32 and the column-direction wiring 34 intersect each other. On the other hand, the faceplate 40 includes the glass substrate 41, the light emitter such as a fluorescent material layer 47, and the metal back 45. The fluorescent material layer 47 includes a fluorescent material and a distance specifying member (such as a light absorption member) inside the glass substrate 41. The light emitter (such as a fluorescent material) emits light by the electron beam irradiation. The distance specifying member restrains color mixing of the fluorescent material while suppressing reflection of outside light. The metal back 45 reflects the light which is emitted from the fluorescent material layer 47 toward the outside of the display panel. Usually the distance specifying member is formed in a shape of a matrix or a stripe which is made of a black material (such as graphite flake). High voltage is applied to the fluorescent material layer 47 and the metal back 45 from the external high-voltage power supply 46 through a high voltage-in terminal, and the fluorescent material layer 47 and the metal back 45 form an anode electrode. In a process of manufacturing the fluorescent material layer 47, it is possible to adopt a process of forming the distance specifying member as the member having a plurality of openings and then arranging the light emitter (fluorescent material) in each opening. Therefore, the distance specifying member can also be referred to as the member having the plurality of openings.
In the image display device having the above structure, an electric field is generated between the rear plate 31 and the faceplate 40 by applying the high voltage (sometimes referred to as “accelerating voltage” or “anode voltage”) to the metal back 45 which is of a part of the anode electrode. The electric field causes the electron-emitted from the electron-emitting device 33 to collide with the fluorescent material, which allows the fluorescent material to emit the light to display an image. At this point, because brightness of the image display device depends largely on the accelerating voltage, in order to increase the brightness, it is necessary to increase the accelerating voltage. Further, in order to realize a reduction in thickness of the image display device, it is necessary to decrease the distance between the rear plate 31 and the faceplate 40. This results in the generation of the considerably high electric field between the rear plate 31 and the faceplate 40.
The flat panel display in which the high electric field is applied between the rear plate and the faceplate in the above-described way is disclosed in Japanese Patent Application Laid-Open No. 10-326583.